The present invention relates, to infant incubators and, in particular, to apparatus for regulating the heating of the air which is circulated through an infant incubator and introducing the heated air into the space in which an infant is placed for treatment.
The most common way for regulating the heating of the air which is circulated through an incubator is to control the power delivered to the heater. An alternative approach, although not as common, is to control the speed of a fan which forces air across the heater and through the incubator. Typically, a temperature sensor, located in the space in which an infant is placed for treatment, and a temperature sensor, attached to the infant, serve as the control for establishing and maintaining the desired temperature of the air to which the infant is exposed.
Incubators have access doors which, when opened, permit access to an infant by those attending to the infant. When an access door is opened, the ambient air can enter the incubator space in which the infant has been placed and change the conditions of the air to which the infant is exposed. As a result, incubators have been arranged with openings extending along the access doors through which incubator air passes to develop warm air curtains which are intended to serve as shields to inhibit the ambient air from entering the space in which the infant has been positioned.
Some incubators are arranged to sense either the access door being opened or a change in temperature in the space in which the infant has been placed and change the heating and delivery of the air which is circulated through the incubator to compensate for the change in conditions by the entry of the ambient air.
An infant incubator, constructed in accordance with the present invention, includes a hood having an access door in a wall thereof and a base upon which the hood is mounted and having a deck which with the hood defines an enclosure. The deck has openings through which air enters and leaves the enclosure. Also included in this incubator are a heater within the base for heating the air and a fan for supplying air to the heater and heated air from said heater into the enclosure through at least one of the openings and for returning air from the enclosure to the heater through at least one of the openings. An infant incubator, constructed in accordance with the present invention, further includes sensing means responsive to movement of the access door for sensing when the access door is opened and control means responsive to the sensing means for increasing the heat generated by the heater and increasing the speed of said fan when the access door is opened.